Fatigue, a multidimensional and pervasive state (Piper, 1992), is the number one complaint of mothers and fathers after the birth of a baby. Fatigue decreases new parents' ability to cope with the tasks of parenting as well as with the task of maintaining their relationship. Research has identified many factors that influence prenatal and postpartum fatigue without differentiating between the effects of fatigue on new mothers versus new fathers. This second study in a program of research is designed to determine (a) if new mothers and new fathers experience fatigue differently during the ninth prenatal month and the first four months of the postpartum period, (b) to what extent factors relating to childbirth, infant characteristics, and parental characteristics lead to the development of postpartum fatigue, and (c) the effect of fatigue on new mothers' and new fathers' satisfaction with each other and with their infant, and on their confidence regarding infant care. Using a longitudinal, repeated measures design, men's and women's level of morning, afternoon, and evening fatigue will be examined in light of childbirth experiences, type of infant feeding method, infant temperament, age, sleep, use of outside resources, and self-report of depression. The extent to which fatigue affects the parenting outcomes of marital satisfaction, satisfaction with the infant, and infant care self-efficacy will be explored from the ninth prenatal month to the fourth month of the postpartum period. Fifty couples from rural and urban health care practices who are expecting their first baby will be recruited to participate in this study. Descriptive summary statistics, repeated measure analyses of variance (AN0VAs), and time-fixed correlational analyses will be used to test the aims of this study. The findings of this study will direct the development and implementation of nursing interventions to reduce the negative effects of fatigue on the functioning of new parents.